August 11-15, 2014


Massive White Dwarfs with Infrared Excesses

Sara Barber (University of Oklahoma)

Mukremin Kilic (University of Oklahoma)

Circumstellar dust around a white dwarf originates from the tidal disruption of asteroids and is thus used as a tracer for remnant planetary systems. In the massive stellar regime, where main-sequence planet searches break down, post-main sequence planetary systems can be more easily found. For Cycle 9 of the Spitzer mission we were awarded 15 hours to search 100 massive white dwarfs from the SDSS in the 4.5 micron IRAC band for excess emission in order to constrain the frequency of disks at massive WDs, and the frequency of planets at their massive progenitors, for the first time. Our sample is selected to have mass greater than 0.8 M (~3.5Msol progenitor mass) and Teff = 9500 - 22,500K. In Cycle 10, we are currently following up on 23 of these targets found to exhibit excess emission in infrared to allow for robust characterization of the excess. The most up-to-date results from this project will be presented.

Mode of presentation: oral